US 4,398,813 A · Photographic camera

Abstract

A photographic camera with automatic setting of diaphragm and exposure time. A light sensitive circuit generates pulses and is connected to a diaphragm counting stage for comparing signals from the light sensitive circuit with preset signals in the diaphragm counting stage and for providing a stop pulse to an electromagnetic diaphragm setting stage. A counter is connected to a pulse generator and to the diaphragm counting stage in a stop control connection. A start control provision connects the output of the diaphragm counting stage to an exposure time forming stage. The exposure time forming stage can be connected to the counter for providing automatic setting of the time determining part of the exposure time forming stage depending on the counting state of the counter. A shutter opening member can be connected to the diaphragm counting stage for receiving a control signal for the release part of the shutter opening member.

Claims26

Dependent claims

A photographic camera having an aperture diaphragm, a shutter control means and a diaphragm setting device, said diaphragm setting device comprising a light-sensitive circuit generating pulses;

an electromagnetic diaphragm setting stage;
a diaphragm counting stage connected to the light-sensitive circuit for comparing signals from the light-sensitive circuit with preset signals and for providing a stop pulse to the electromagnetic diaphragm setting stage;
a pulse generator;
a time counter connected via a stop control connection to the pulse generator and to the diaphragm counting stage;
and said shutter control means comprising an exposure time forming stage connected via a start control connection to the output of the diaphragm counting stage.

2 more elements

A method for controlling the exposure provided by a photographic camera comprising

converting light radiation into electrical pulse signals;
comparing the pulse signals with a preset count in a diaphragm counting stage;
generating a stop pulse upon finding equivalence between the pulse signals and a preset condition;
feeding the stop pulse to a diaphragm setting stage;
feeding a control signal from the diaphragm counting stage to the release part of a shutter opening member;
switching on a counter having a timing pulse generator at about the same time as the diaphragm counting stage;
stop-controlling the counter with the output of the diaphragm counting stage;
start-controlling an exposure time forming stage with the transfer output of the diaphragm counting stage;
and
automatically adjusting the value of the time determining member of the exposure time forming stage depending on the counting state of the counter.

7 more elements

Dependencies are inferred from the claim text.

Photographic camera

Life of this patent

Photographic camera

Life of this patent

Abstract

Claims26